a. Field of the Invention
The present invention relates to a retrofocus type large-aperture, ultra wide angle photographic lens having a relative aperture ratio of 1:2 and field angle of 92.degree..
B. Description of the Prior Art
U.S. Pat. No. 3,512,874 and Japanese Patent Publication No. 46-13477 have heretofore disclosed retrofocus type photographic lenses which are similar to that according to the present invention hereinafter described. However, such conventional photographic lenses were not sufficiently compact in their designs and had very small aperture ratios.